Blackboards, electronic whiteboards and other two-dimensional free form workspaces have long been used for supporting brainstorming, sensemaking, and other generative tasks where information is created and organized incrementally. Sensemaking is a term used to describe activities that interweave retrieving, creating and using information. As the amount of information placed in these workspaces grows, the competition for display space increases. If users need to interrupt their ideation to rearrange the information in the workspace, make space for new information, or perform other “housekeeping” functions to enable use of the workspace, they risk disruption of their train of thought or “losing the flow” resulting in the possible loss of ideas. Often, the information contained in the workspace is represented as graphical objects. Thus, there is a general need in systems providing a two-dimensional (2D) workspace for techniques that provide intuitive and timely manipulation and interaction of graphical objects.
The use of computer controlled two-dimensional workspaces for organizing information is well known in the art. Some of these systems include the Alternate Reality Kit (SMITH, R. Experiences with the Alternate Reality Kit: an example of the tension between literalism and magic. Proceedings of CHI/GI '87, April 1987, pp. 61–67), Aquanet (MARSHALL, C. AND ROGERS, R. Two Years Before the Mist: Experiences with Aquanet, Proceedings of the ACM Conference on Hypertext, November 1992, pp. 53–62), Cognoter (STEFIK, M., BOBROW, D., FOSTER, G., LANNING, S. AND TATAR, D. WYSIWIS Revised: Early Experiences with Multi-User Interfaces. Proceedings of the Conference on Computer-Supported Cooperative Work, December 1986, pp. 276–290), Flatland (MYNATT, E., IGARASHI, T., EDWARDS, W., LAMARCA, A. Flatland: New Dimensions in Office Whiteboards. Proceedings of the CHI 99 Conference on Human Factors and Computing Systems, May 1999, pp. 346–353), MUSE (FURNAS, G. AND ZHANG, X. MuSE: A Multiscale Editor, Proceedings of UIST '98, November 1998, pp. 107–116), PowerPoint (MICROSOFT POWERPOINT. http://www.microsoft.com/office/powerpoint/), Storyspace (EASTGATE SYSTEMS STORYSPACE. http://www.eastgate.com/Storyspace.html), Tivoli (PEDERSON, E., McCALL, K., MORAN, T. AND HALASZ, F. Tivoli: An Electronic Whiteboard for Informal Workgroup Meetings, Proceedings of the Conference on Human Factors in Computing Systems, April 1993, pp. 391–398), VIKI (MARSHALL, C., SHIPMAN, F., AND COOMBS, J. VIKI: Spatial Hypertext Supporting Emergent Structure, Proceedings of the 1994 ACM European Conference on Hypermedia Technology, September 1994, pp. 13–23), and Web Squirrel (EASTGATE SYSTEMS WEB SQUIRREL http://www.eastgate.com/squirrel/Welcome.html).
In order to minimize “losing the flow” when using such systems, the manner in which a user interacts and the system responds is critical. A number of techniques have been disclosed in the art which purportedly facilitate the use of such systems. Some techniques provide for certain operations to be automatically performed. One such operation is the handling of related information in some coordinated fashion, e.g. as a list or group. For example, PowerPoint, Tivoli, and VIKI all have notions of a list structure to automate the alignment and ordering of list items. Although PowerPoint and Tivoli also use this list structure to assist in inserting items into the list, neither of these systems provide an interactive preview of the resulting insertion. Such a preview is useful in understanding the effect of updating a list structure. Storyspace and VIKI also have the notion of a subspace (i.e. a separate and distinct interaction space within another space) to automate the maintenance of a spatial, hierarchical collection of objects.
Several systems have also employed features for automating object interactions. The Flatland system uses a bumping concept to avoid the occlusion of objects on a whiteboard surface. Moving or growing an object could cause it to transitively bump other objects and if an object hits the edge of the whiteboard (i.e. the visible display area) it would automatically shrink. Data Mountain (ROBERTSON, G., CZERWINSKI, M., LARSON, K., ROBBINS, D., THIEL, D., VAN DANTZICH, M. Data Mountain, Using Spatial Memory for Document Management, Proceedings of UIST '98, November 1998, pp. 153–162) also employs bumping to reduce the occlusion of web pages on an inclined plane; facile movement and placement of the pages is permitted while keeping at least some part of the page visible. The Alternate Reality Kit provided a more diverse collection of object interaction contracts, such as gravity or spring forces, to simulate object interactions in a virtual world with alternate physics principles. Lastly, PowerPoint provides automatic panning, a type of object interaction to keep the current text entry point in view. However, PowerPoint does not return your position to the original viewpoint when the text entry is completed.
Another technique known in the art is to provide specialized tools to enable movement or the organization of objects. The alignment stick (RAISAMO, R. AND RAIHA, K. A New Direct Manipulation Technique for Aligning Objects in Drawing Programs. Proceedings of UIST '96, November 1996, pp. 157–164 and RAISAMO, R. An alternative way of drawing. CHI '99 Proceedings, 1999, 175–182) provides a tool for providing direct manipulation of layouts. The broom alignment tool (ROBBINS, J., KANTOR, M. AND REDMILES, D. Sweeping away disorder with the broom alignment tool. Conference Companion of CHI '99) is similar to the alignment stick, but it can also distribute objects along its length. The user can cycle through different distribution policies by pressing the space bar. Furthermore, moving the broom backward automatically undoes the alignment operation.